Cancer News

Contralateral Breast Cancer Risk High With Gene Mutation

-- A. Agrawal, PhD

Wednesday, October 28, 2009

WEDNESDAY, Oct. 28 (HealthDay News) -- Women with cancer in one breast who come from families with a hereditary breast cancer mutation have a nearly 50 percent long-term risk of developing cancer in the opposite breast, particularly if they are younger at first diagnosis, according to a study published online Oct. 26 in the Journal of Clinical Oncology.

Monika K. Graeser, from University Hospital Cologne in Germany, and colleagues assessed the long-term risk of contralateral breast cancer in 2,020 women (978 patients, 1,042 relatives) with unilateral breast cancer from 978 families with a pathogenic mutation in the BRCA1 or BRCA2 gene.

The researchers found that the patient group had a 47.4 percent cumulative risk of contralateral breast cancer 25 years after the first cancer. The risk was higher in families with BRCA1 mutations (hazard ratio, 1.58) compared with BRCA2 mutations. Younger patients were at significantly higher risk of contralateral breast cancer if they had a BRCA1 mutation, with 62.9 percent with a mutation developing contralateral breast cancer if they were less than 40 years old at first diagnosis, compared with only 19.6 percent if they were older than 50 years old.

"Contralateral breast cancer risk depends on age at first breast cancer and on the affected BRCA gene, and this risk should be considered in treatment planning," Graeser and colleagues conclude. "To our knowledge, this study is the first to show that patients from families with BRCA1 mutations face a significantly higher contralateral breast cancer risk compared with patients from families with BRCA2 mutations."